I don't believe that the TPS was designed and integrated as a sensor which can sense a position data inaccuracy and throw a code. My understanding is that whatever data (whether accurate to the actual throttle position or not) the TPS sends back to the computer (PCM), the PCM simply uses that data and regulates operating parameters accordingly.

On the other hand, if the TPS was simply not sending any data to the PCM (or data not within the correct range of the sensor), then the PCM would probably throw a code.

It could be. Unfortunately, the thing about faulty micro-sensors is that the faults may or may not appear in a predictable/reliable manner.

 

I never received a check engine light for my TPS. I can say though when I replaced it, it made a world of difference in driveability including idle speed, transmission shifting, gas mileage, power, etc...

 

This issue had gone away for a couple years and is back again, I hadn't gotten the TPS replaced. Here are some new things I learned:

• It happens between 1k and 1.5k RPMs
  • If I push harder on the throttle it can get to 2k and stop studdering
• It happens with or without cruise on
• It always happens after driving longer distances (I don't drive this vehicle very far)
  • It usually starts on the interstate after driving more than 20 miles
  • It will continue at lower speeds once exiting interstate.
• If I adjust my speed on the interstate so that my throttle is barely pressed, it seems to stop

This past week I was driving on the interstate and it started happening really bad followed by my engine light flashing. Then about 30 seconds later the engine light stopped flashing, it went completely off. I went to O'Reilly's to get the code checked which rendered "P0594 Cruise Control Servo Control circuit / open".

Do you think my issue here is actually my cruise control even though it happens while I'm manually controlling my throttle? Or do you think the TPS is still the root issue and the error code is the cruise control noticing the TPS is being weird?

Thanks,
Jake

 

Flashing CEL means engine is misfiring. That would coincide with the lack of power. Pressing the gas a bit, gives it a quick shot of extra gas, to get the engine to accelerate. The cruise code I think is just a coincidence.

 

You're saying it's not my TPS, right? Or are you saying my TPS is causing the lack of power?

 

Could be any number of things at this point. See if there are any pending codes. That may tell you which cylinders were misfiring. But, yes, it *could* be TPS...... That would explain the cruise codes as well, PCM is trying to control the module, but, not seeing any changes on TPS. Sure wouldn't hurt to test it.

 

The only pending codes were brake fluid low and the cruise control one. I was surprised there wasn't a code about the engine light flashing.

 

Yeah, me too..... Test the TPS, and see what you get.

 

How do I test it?

 

There should be three wires. One will be 5 volt signal from PCM, one will be ground, the third will be a modified signal going back to the PCM. (it should range from somewhere under 1 volt at closed throttle, to somewhere over 3.5 volts at wide open throttle. As to which is which..... That I don't know. Got a wiring diagram?